i'm new to this site and had a few questions about pit bulls. what is the difference between the American Pit Bull Terrier and the American Staffordshire Terrier, or isn't their one??? also what is the size and weight these dogs get???

thanks for the welcome. i tried searching but couldn't find anything. the reason i was asking is because my sister just got a pit bull puppy and the father was big(probaly around 70 pounds and as tall a golden retriever) the female was smaller. people have been telling her that she cant have a pure pit bull because they are smaller, which is what i always thought too.